He’s been shuffling the buck

I think this mix-up is caused by two similar looking four letter words – buck and deck. Both expressions also have similar meanings – not addressing issues squarely. Finally, maybe the brain reads “shuffle” equating to shuffleboard and then thinks pucks and it comes out buck. Is that a stretch? As “ol pal” notes, this mash up probably includes the phrase “passing the buck” as well, and my guess is that this is what the speaker intended to say. Again, passing is similar to shuffling as in shuffleboard (pushing or passing the shuffleboard puck).